Door latch



O. STINSON Aug. '30, 1938.

DOOR LATCH Filed May 24, l957 INVENTUR OLIVER STI NSON A TTORNE Y Patented Aug. 30, 1938 urrao s'rAras ATENT OFFlCE I 2,128,439 DOOR LATCH Application May .24, 1937, Serial No. 144,421

4 Claims.

This invention relates to improvements in door latches or locks.

In large refrigerators, incubators and similar apparatus, it is necessary to provide means for latching the doors in such a way that they will be positively held in closed position and will be forced against the stops on the door frame so as to secure a tight joint.

It is the object of this invention to produce IO' a door latch or look that shall be especially well adapted for use on heavy heat insulated doors such asare used in large capacity incubators and large refrigerators, but which can also be applied to any other door where a secure latching device is desired.

Another object of the invention is to produce a latching device that is especially Well adapted for, use with double doors.

A further object is to produce a latch of simple and economical constructionbut of great strength that shall be positive in its action and which will not work loose.

A further object is to produce a latch that employs rotatable latching devices that cooperate with stationary wedges on the door frame in such a manner that a large multiplication of the force can be obtained.

The above and other objects that may become apparent as the description proceeds are at- 30. tained by means of a construction and a combination of parts .that will now be described, referencefor this purpose being had. to the accompanying drawing in which the invention has been illustrated in its present preferred embodiment and in which:

Figure 1 is an elevation showing the inside of a door equipped with the present invention;

Figure 2 is an end elevation looking towards the left in Fig. 1; 1

Figure 3 is a section taken on line 3-3, Fig. 2, and shows the latch in operative position;

Figure 4 is a section taken on line 44 Fig. 3, and shows the wedge with which the latching member cooperates;

Figure 5 is a section taken on line 5-5 Fig. 1,

with the door in closed position and shows the Latches A and C are identical in construction and have been shown in section in Fig. 5, which serves to illustrate both of them. From the drawing, it will be seen that a round plate 8 is embedded in the inner surface of the door and held in place by screws 9. Plate 8 has a hub ID that extends into the door and which has a threaded opening for the reception of the bolt II. The latch member I2 is preferably circular and of the same diameter as the plate 8. The latch member l2 has a central hub l3 and two smaller hubs or bosses l4 that are positioned on diametrically opposed points. Each latch member is provided with a lug I5 that is offset from its outer surface in the manner clearly shown in Fig. 5. Secured to the top of the door frame, or opening, is a wedge [6 like that shown in Fig. 6, and a similar wedge is secured to the bottom of the door frame. The two wedges are identical except that one is a right and the other a left. Each wedge has a part I! that is thinner than the remainder and is provided with openings for securing screws l8, the thicker portion may also have openings for securing screws.

In Fig. 3 the operating means has been shown, and this will now be described. A handle I9 has a cylindrical bolt 20 integrally attached to it and this extends at right angles and passes through an opening in the door, as clearly shown. A circular flange 2i surrounds the bolt and engages the outside of the door. Embedded in the inner surface of the door is a round plate 8A that is identical with the corresponding plateshown in Fig. 5, except for this that the. central opening is not threaded. The inner end of the bolt 20 is non-circular in cross section and secured to this portion is'a latch member IZA that is similar to the corresponding member shown in Fig. 5, except for this that it is provided with a lug 22 that engages the stop 23 when the parts have been moved to door latching position. The side of the door frame has a wedge 24 securedto it, as shown in Fig. 4 for engagement by the latch lug I5A. A nut 25 is secured to the threaded end of bolt 20 and holds the operating means in assembled position. A deformed spring washer 26 is positioned between the plate 8A and the latch member IZA, as shown in Fig. 3 and serves to provide friction sufficient to hold the parts in adjusted position.

Connecting rods join the two bosses on latch member I2A, each with a boss I4 on a latch member l2.

The connecting rods each comprise a tubular section 2'! having a portion at each end interiorly threaded. A bronze extension member 28 is threaded in each end and held in adjusted position by a nut 29. The parts are so adjusted that when the handle I9 is vertical, as in Fig. 2, the lugs l5 on latch members I2 are practically vertical and each engages the inclined surface of a wedge It, in the manner shown in Figs. 6 and '7. When handle i9 is in vertical position, the lug 22 engages the stop 23 and limits the rotation of the latch member 8A. The lug l5A on member !2A, latch B, cooperates with a wedge 24 that is attached to the side of the door frame, where one door is used, or to the edge of the second door, where two doors are employed. Where two doors are employed, both are held close by thelatches on the one door.

Attention is called to the factthat the latch members l2, 42A rotate instead of move longitudinally and the lugs I5, I5A therefore have a long relative movement along the wedge surface with which it cooperates. The inclination of the wedges may therefore be smaller than if the movement were short and a greater pressure can therefore be obtained from the same amount of effort.

In the arrangement illustrated, the closing or latching is efiected by compression of tubes. 2'! and consequently the opening is effected by tension in the connecting rods for the reason that it requires a greater force to release the latches from a stationary position than to close them.

Referring now more particularly to Fig. 1 it will be noted that the bronze extension members 28, that are connected with latches A and C, are provided with projections, not numbered, that engage with the hubs l3 of the latch members l2, and limit the opening movement of the latch.

The latch operating mechanism B with its deformed friction washer 26 and the stops 22 and 23 are also considered to be importantin this combination and novel.

Having described the invention what is claimed as new is:

1. A device for operating a latch positioned on the inside of a door by means accessible from the outside, comprising a bolt extending through an opening in the door, the bolt having a handle secured to the outer end thereof, a circular flange integral with the bolt for engagement with the outside of the door, a bearing disk secured to the inside of the door, said disk having on one side a positioning hub that extends into the door, the hub having an opening forming a bearing for the bolt, a crank disk non-rotatably secured to the inner end of the bolt and a deformed spring washer between the two disks to produce friction tending to keep the bolt and crank disk from accidental rotation, the crank disk having a crank pin for engagement with one end of a connecting rod.

2. A device for operating a latch positioned on the inside of a door by means accessible from the outside, comprising a bolt extending through an opening in the door, the bolt having a handle secured to the outer end thereof, a circular flange integral with the bolt for engagement with the outside of the door, a bearing disk secured to the inside of the door, said disk having on one side a positioning hub that extends into the door, the hub having an opening forming a bearing for the bolt, a crank disk non-rotatably secured to the inner end of the bolt, a deformed spring washer between the two disks to produce friction tending to keep the bolt and crank disk from accidental rotation, the crank disk having a crank pin for engagement with one end of a connecting rod, and a lug projecting therefrom for engaging a stop carried by the door to limit rotary movement in one direction.

3. A device for operating a latch positioned on the inside of a door by means accessible from the outside, comprising a bolt extending through an opening in the door, the bolt having a handle secured to the outer end thereof, a circular flange integral with the bolt for engagement with the outside of the door, a bearing disk secured to the inside of the door, said disk having on one side a positioning hub that extends into the door, the hub having an opening forming a bearing for the bolt, a crank disk non-rotatably secured to the inner end of the bolt, .a deformed spring washer between the two disks to produce friction tending to keep the bolt and crank disk for accidental rotation, the crank disk having a crank pin for engagement with one end of a connecting rod, and a lug projecting therefrom to engage a stop carried by the door, to limit rotation of the crank disk inone direction, and a second lug offset from the plane thereof and extending radially therefrom for engaging with a stationary wedge.

4. A latch comprising in combination, a rotatable latch member having a hub concentric with its axis of pivotation, a connecting rod having one end pivotally attached to the latch member at a point radially removed from the hub, and means for reciprocating the connecting rod whereby the latch member will be oscillated about its pivot, the end of the connecting rod projecting beyond its pivot point a distance greater than the radial distance from the pivot to the hub whereby it will engage the latter and act as a stop when the connecting rod moves in one direction.

OLIVER STINSON. 

